(652b) Free Surface Profiles in Centrifuge Filtration at Low Speeds – Theoretical and Computational Solutions

The speed of rotation of the centrifuge plays an important role in the filtration rate of any centrifuge based filtration systems. As the filtration proceeds, a wet cake starts to form in the centrifuge. The speed of rotation also plays a very important role in the compressibility of this wet cake. For very compressible cakes, the centrifuging is done at low speeds of rotation to minimize compression of the cake. If the speed is too low, it could lead to loss of slurry from the bottom of the centrifuge. Hence it is important to understand the effect of speed of rotation of the centrifuge on the liquid free surface profile. In this paper, theoretical solutions are presented for various scenarios of centrifuge operation. These results are compared with computational fluid dynamics (CFD) based predictions for the free surface profiles. This analysis helps in determining the optimum centrifuge speeds for filtration of very compressible cakes.